Opening ports on a private cluster

If you are installing in-cluster Anthos Service Mesh on a private cluster, you must open port 15017 in the firewall to get the webhooks used with automatic sidecar injection (auto-injection) and configuration validation to work.

You can either add a firewall rule or update the firewall rule that was created automatically when you created the private cluster. The following steps describe how to update the firewall rule. The update command replaces the existing firewall rule, so you need to include the default ports 443 (HTTPS) and 10250 (kubelet) as well as the new ports that you want to open.

Find the source range (master-ipv4-cidr) of the cluster. In the following command, replace CLUSTER_NAME with the name of your cluster:
```
gcloud compute firewall-rules list --filter="name~gke-CLUSTER_NAME-[0-9a-z]*-master"
```
Update the firewall rule. Choose one of the following commands and replace FIREWALL_RULE_NAME with the name of the firewall rule from the output of the previous command.
- If you only want to enable auto-injection, run the following command to open port 15017:
```
gcloud compute firewall-rules update FIREWALL_RULE_NAME --allow tcp:10250,tcp:443,tcp:15017
```
- If you want to enable auto-injection and the istioctl version and istioctl ps commands, run the following command to open ports 15017, 15014, and 8080:
```
gcloud compute firewall-rules update FIREWALL_RULE_NAME --allow tcp:10250,tcp:443,tcp:15017,tcp:15014,tcp:8080
```